Biomedical subjects
Publications and source records attributed to Maurizio Margaglione.
Discrepancies about a possible relationship between prothrombotic mutations and a decreased uteroplacental blood flow are present in literature. We prospectively evaluated a cohort of pregnant women (n = 41) with bilateral uterine artery notches and found that women with inherited thrombophilia showed a sixfold higher risk to have an adverse outcome than women without.
A new analytical determination method of homocystine in human plasma has been developed. The method utilises liquid chromatography coupled to ionspray tandem mass spectrometry. Quantitative analysis was achieved using as an internal standard homocystine-d8. Mass spectrometer operated in the multiple reaction mode: homocystine and homocystine-d8 were detected through the transition from the precursor to the product ion (from m/z 269.3 to 90.0, and m/z 277.3 to 94.0, respectively). The method is extremely sensitive, with limit of detection in the range of 6 fmol/L. The interassay and intraassay coefficients of variation for homocystine were 6.22% and 3.4%, respectively. The accuracy for the added homocystine ranged from 85% to 110%. High specificity of tandem mass spectrometry coupled with a fast chromatographic process is suitable for a rapid and reliable assay of homocystine.
BACKGROUND: It is unclear wheather the association between C-reactive protein (CRP) and incident coronary events is free from bias and confounding. Individuals homozygous for a +1444C>T polymorphism in the CRP gene have higher circulating concentrations of CRP. Since the distribution of this polymorphism occurs at random during gamete formation, its association with coronary events should not be biased or confounded. METHODS: We calculated the weighted mean difference in CRP between individuals with variants of the +1444C>T polymorphism in the CRP gene among 4,659 European men from six studies (genotype-intermediate phenotype studies). We used this difference together with data from previous observational studies to compute an expected odds ratio (OR) for non-fatal myocardial infarction (MI) among individuals homozygous for the T allele. We then performed four new genetic association studies (6,201 European men) to obtain a summary OR for the association between the +1444C>T polymorphism and non-fatal MI (genotype-disease studies). RESULTS: CRP was 0.68 mg/l [95% confidence interval (95% CI) 0.31-1.10; P = 0.0001] higher among subjects homozygous for the +1444-T allele, with no confounding by a range of covariates. The expected ORs among TT subjects for non-fatal MI corresponding to this difference in CRP was 1.20 (95% CI 1.07-1.38) using the Reykjavik Heart study data and 1.25 (1.09-1.43) for all observational studies to 2004. The estimate for the observed adjusted-OR for non-fatal MI among TT subjects was 1.01 (95% CI 0.74-1.38), lower than both expected ORs. CONCLUSIONS: A common CRP gene polymorphism is associated with important differences in CRP concentrations, free from confounding. The null association of this variant with coronary events suggests possible residual confounding (or reverse causation) in the CRP-coronary event association in observational studies, though the confidence limits are still compatible with a modest causal effect. Additional studies of genotype (or haplotype) and coronary events would help clarify whether or not the link between CRP and coronary events in observational studies is causal.
OBJECTIVE: To evaluate the role of different polymorphic gene variants involved in homocysteine metabolism and plasma levels of homocysteine, folate and vitamin B12 in families from southern Italy with neural tube defects (NTDs). METHODS: Eighteen fathers, 15 NTD children and 60 women who had conceived NTD foetuses were investigated. A group of 100 adults and 43 apparently healthy children was used as control. At the time of blood draw, none were taking vitamin pills or nutritional supplements. RESULTS: Among controls, 79 (55.2%) were heterozygous for C677T MTHFR variant and 26 (18.2%) were TT homozygous. Among the cases, 35 (61.4%) out of 57 mothers and 7 (38.9%) out of 18 fathers carried the T allele; 12 (21.1%) mothers and 2 (11.1%) fathers had the TT genotype. Four (26.7%) out of 15 probands were TT homozygous and 11 (73.3%) were heterozygous (Fisher exact test p = 0.025). No significant difference between groups was observed for the 1298C MTHFR variant and CBS haplotypes. Median homocysteine in NTD children was significantly higher (10.0 micromol/L) than that of controls (median 4.5 micromol/L, Mann-Whitney p < 0.05). Folate and B12 were not different among groups. CONCLUSIONS: The T677 MTHFR allele is significantly associated with the occurrence of NTDs; no significant association has been observed with other genetic determinants analysed. Homocysteine levels in children with NTDs are significantly higher than those of the paediatric population from the same geographical area.
In the atherosclerotic plaque, cyclooxygenase-2 (COX-2) catalyzes prostaglandin E formation, which acts as a pro-atherogenic factor. A polymorphism, G/C -765, within the COX-2 promoter region modulates gene expression and the risk of cerebrovascular disease. We have evaluated the relation between COX-2 G/C -765 genotypes and the occurrence of cerebrovascular ischemia. We evaluated the COX-2 G/C -765 polymorphism in 110 consecutive patients with a documented history of acute ischemic cerebrovascular disease, in 110 age-matched and sex-matched subjects without such history, and in a general population (n = 324) from the same ethnical background. The frequency of the COX-2 -765C allele in patients [0.21; 95% confidence interval (CI), 0.16-0.26] was similar to those found in controls (0.28; 95% CI, 0.22-0.34) and in the general population (0.26; 95% CI, 0.23-0.29). Carriers of the CC genotype differed between patients (0.02; 95% CI, 0.00-0.05) and controls [0.10 (95% CI, 0.04-0.16), P = 0.019; odds ratio, 0.17 (95% CI, 0.04-0.79)] or the general population [0.08 (95% CI, 0.05-0.11), P = 0.023; odds ratio, 0.22 (95% CI, 0.05-0.95)]. In a multiple logistic regression analysis adjusted for confounding variables, smoking status (P < 0.001), atrial fibrillation (P = 0.004) and COX-2 G/C-765 polymorphism (P = 0.016) independently contributed to cerebrovascular ischemia, with CC carriers exhibiting a lower risk (odds ratio, 0.07; 95% CI, 0.01-0.61). Our data show an association between the COX-2 G/C-765 gene polymorphism and cerebrovascular ischemia, suggesting that the COX-2 gene is a susceptibility locus for the risk of cerebrovascular ischemic disease.
Inherited abnormalities of fibrinogen present a high variability in penetrance and expressivity, and clinical manifestations vary from severe bleeding or thrombosis to asymptomatic This variability makes clinical and genetic counseling more difficult. We report the experience of a clinical group working in specialist centers in Southern Italy on a series of consecutive patients presenting with congenital abnormalities of fibrinogen. Over 10 years, 18 patients were diagnosed to carry a congenital abnormality of fibrinogen. These patients and 26 first-degree relatives were investigated in-depth to fully characterize the nature of their abnormal fibrinogen levels. A gene mutation was identified in 15 patients (four afibrinogenemic patients, three hypofibrinogenemic patients, and eight dysfibrinogenemic patients). A new mutation was found in four of them: Aalpha Arg159Stop in one afibrinogenemic patient, Aalpha Arg104Cys in two hypofibrinogenemic patients, and Aalpha Pro270Thr in one dysfibrinogenemic patient. While all afibrinogenemic patients had clinically important bleeding, participants presenting with hypofibrinogenemia remained asymptomatic. In the presence of the synthesis of an abnormal molecule, the clinical phenotype was not strictly related to plasma fibrinogen levels but was associated with the molecular defect, most carriers remaining asymptomatic. Personal and family histories of bleeding and thrombosis are important for the clinical management of patients presenting with congenital abnormalities of fibrinogen. Biochemical and genetic investigations may be a useful guide for decision-making, providing additional steps in the assessment of the risk of patients presenting with low levels of a normal molecule (hypofibrinogenemia and afibrinogenemia) and with an abnormal molecule (dysfibrinogenemia), respectively.
It was the aim of the present study to investigate factor II levels in liver cirrhosis (LC) patients with portal vein thrombosis (PVT) carrying the heterozygous G20210A prothrombin (PT) mutation. Plasma concentrations of factor II, VII, X, V, protein C (PC) total protein S (tPS) antithrombin (AT) and D-dimers (DD) were measured in 13 LC patients with PVT heterozygous for PT G20210A, in 13 LC patients with PVT without PT G20210A and in 13 LC controls matched by age, sex and Child-Pugh score. Crude factor II and factor II/DD ratio were highest in LC patients with PVT heterozygous for PT G20210A (p = 0.03 and p = 0.02 respectively). The factor II/PC ratio, expression of a procoagulant/anticoagulant imbalance was highest in the same group (p = 0.0008). Plasma factor II levels are elevated in LC patients heterozygous for PT G20210A and may favour PVT.
Hyperhomocysteinemia could play a similar role in the placenta to that played in adults at risk of thrombosis. Moreover, hyperhomocysteinemia in women is described to be associated with the birth of small for gestational age (SGA) newborns, although there are discrepancies on this issue. To date, there is no biochemical marker predictive of SGA in a given pregnancy. We verified the presence of a relationship between homocysteine in amniotic fluid at mid-pregnancy and birth-weight. Amniotic fluid was obtained from 459 healthy women undergoing midtrimester amniocentesis (17.1 +/- 1.2 weeks) because of maternal age. Homocysteine levels were measured in 434 (10 twin) pregnancies. In addition, femur length (FL) and biparietal diameter (BPD) were measured. Outcome of pregnancy was recorded. 233 (53.7%) foetuses were males, 201 (46.3%) females. The mean homocysteine concentration was 1.04 +/- 0.72 microM, (95% C.I. 0.43-2.41). An univariate analysis showed the presence of an association with gestational age, FL, BPD. A multiple linear regression showed that homocysteine levels were significantly associated with FL (p < 0.001) and BPD (p = 0.011). After excluding twin pregnancies, 31 newborns (7.3%) were classified as SGA. Mean birth-weight was 2390 g in SGA, whereas it was 3360 g in 393 adequate for gestational age (AGA) newborns (p < 0.001). The adjusted mean level of homocysteine was significantly lower in AGA (1.01 microM; 95% C.I: 0.94-1.08) than that recorded in pregnancies resulting in a SGA (1.29 microM; 95% CI: 1.05-1.51; p = 0.03). In a large setting, these data provide reference values for homocysteine in amniotic fluids. Moreover, they suggest that homocysteine levels in amniotic fluids may be higher in pregnancies with a SGA newborn.
The Protein S Italian Team (PROSIT) enrolled 79 protein S (PS) deficient families and found 38 PROS1 variations (19 novel) in 53 probands. Of these, 23 variants were selected for expression in'vitro, to evaluate their role as possible causative variants. Transient expression showed high secretion levels (>75%) for three variants, which were considered neutral. Seven missense and five nonsense variants showed low (<or=11%) expression levels and were classified as severe defects. Intermediate expression was observed for eight variants, which were evaluated by factor Va inactivation assay in order to be globally classified as severe or intermediate. Based on the cumulative data, the hazard ratio associated with causative variants was 4.9 (95% CI: 1.4-17.7) for deep vein thrombosis and/or pulmonary embolism, 5.1 (95% CI: 1.1-23.9) for superficial thrombophlebitis, and 4.8 (95% CI: 1.8-13.0) for any venous thrombosis. The hazard ratio for deep vein thrombosis and/or pulmonary embolism in carriers of severe defects only was 7.4 (95% CI: 1.6-24.1). PROSIT showed that dysfunctional variants causing PS deficiency are more common than expected and confirmed that PS deficiency is associated with increased thrombotic risk, although risk assessment is complicated by molecular heterogeneity.
OBJECTIVES: Congenital nephrotic syndrome of the Finnish type (CNF) is a rare autosomal recessive disorder, caused by mutations in the NPHS1 gene, coding for nephrin. The aim of this work was to investigate the disease mutations in a CNF Italian family and to perform genetic prenatal diagnosis in the second pregnancy. METHODS: Polymerase chain reaction (PCR) and automatic sequence analysis were used to screen the CNF Italian family for NPHS1 mutations. RESULTS: Two novel heterozygous mutations, including a single nucleotide insertion (c.248insA) and a missense mutation (p.S572N), were detected in the proband. Molecular prenatal diagnosis was performed on fetal DNA sample: the fetus resulted compound heterozygous for the same proband mutations. CONCLUSION: To the best of our knowledge, this is the first report of a molecular prenatal diagnosis performed in an Italian family with congenital nephrotic syndrome of Finnish type (CNF). Our findings indicate that, even though CNF is not very common outside Finland, availability and reliability of DNA diagnostics are important issues to confirm the AFP results in prenatal diagnosis.
The aim of this study was to compare bleeding and re-thrombosis in primary antiphospholipid syndrome (PAPS), mitral valve replacement (MVR) and inherited thrombophilia (IT) at different oral anticoagulation intensities. It entailed a prospective 8-year follow-up on 67 patients with PAPS, 89 with IT and 24 with MVR. Anticardiolipin (aCL) antibodies detected by Elisa and lupus anticoagulant by clotting assays. At INR 2-3 minor bleeding rate was higher in MVR (33.3) than PAPS (10.9) and IT (4.2)(p<0.0001). At INR 3-4 minor bleeding rate was higher in PAPS (142) than IT (33.3) and MVR (5.8)(p<0.0001). At either INR major bleeding rate were not significantly different across the three groups, but in PAPS major and minor bleeding rates were superior at INR 3-4 than INR 2-3 (p=0.02 and p<0.0001). Re-thrombosis rate was higher in PAPS than IT at INR 2-3 (4.0 vs 0.35) (p=0.01) and at INR 3-4 (10.5 vs. nil). The hazard ratio for re-thrombosis between PAPS and IT was 13 (95% IC 1.6-102.2, p=0.015). By regression analysis, baseline IgG aCL titre (>80 GPL) p=0.001) and male sex (p=0.03) independently predicted re-thrombosis. In conclusion, in PAPS, high intensity oral anticoagulation was not superior to conventional intensity in preventing re-thrombosis but was offset by greater bleeding rates. Male sex and elevated baseline IgG aCL predicted rethrombosis in PAPS that is 13-fold more re-thrombogenic than IT.
BACKGROUND: Although the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism has been identified as an independent cardiovascular risk factor (CRF) in the general population and among uraemic subjects, the validity of this association remains controversial. METHODS: To verify this hypothesis, we enrolled all subjects on maintenance dialysis treatment from a specific Italian district. We also enrolled, from the same area, 1307 subject to serve as controls. Genomic DNA was obtained and MTHFR C677T gene polymorphisms were determined. After a baseline evaluation, patients were followed-up for 37+/-13 months, and all cardiovascular events and causes of mortality were recorded. RESULTS: A total of 461 patients (417 on haemodialysis and 44 on peritoneal dialysis) were investigated, and these included patients with and without cardiovascular diseases at baseline. At enrollment, mean age was 58.8+/-15.6 years and dialytic age was 82+/-69 months. Genotype frequencies were not different between controls and uraemics. During the follow-up, the mean mortality rate was 8.81%/year, with cardiovascular events as the most frequent cause of death (n = 68, 56.6%). There was no relationship between the MTHFR genotype and cardiovascular morbidity, overall mortality or cardiovascular mortality. CONCLUSIONS: In end-stage renal disease, MTHFR C677T polymorphisms were not associated with cardiovascular disease or mortality.
Patients require different warfarin dosages to achieve the target therapeutic anticoagulation. The variability is largely genetically determined, and it can be only partly explained by genetic variability in the cytochrome CYP2C9 locus. In 147 patients followed from the start of anticoagulation with warfarin, we have investigated whether VKORC1 gene mutations have affected doses of drug prescribed to acquire the target anticoagulation intensity. Two synonymous mutations, 129C>T at Cys43 and 3462C>T at Leu120, and 2 missense mutations, Asp38Tyr and Arg151Gln, were identified. None of these mutations was found to affect the interindividual variability of warfarin prescribed. Finally, 2 common polymorphisms were found, 1173C>T in the intron 1 and 3730G>A transition in the 3' untranslated region (UTR). Regardless of the presence of confounding variables, the mean adjusted dose required of warfarin was higher (6.2 mg) among patients with the VKORC1 1173CC genotype than those of patients carrying the CT (4.8 mg; P = .002) or the TT genotype (3.5 mg; P < .001). In the present setting, VKORC1 and CYP2C9 genetic variants investigated accounted for about a third (r2, 0.353) of the interindividual variability. Genetic variants of the VKORC1 gene locus modulate the mean daily dose of drug prescribed to acquire the target anticoagulation intensity.
This is the case of a 28-year-old woman in apparently good health, who had an ischemic stroke and significant proteinuria developed during her first attempt of in vitro fertilization. She was evaluated for inherited and acquired thrombophilia and tested positive for high titer of antiphospholipid antibodies and mild hyperhomocysteinemia. The potential thrombotic risks associated with in vitro fertilization will be discussed.
We evaluated protein Z plasma levels in a group of women with fetal losses (n = 124) and compared them with those in a group of women (n = 60) with uneventful pregnancies. We found that protein Z deficiency is not associated with otherwise unexplained fetal losses.
BACKGROUND/AIMS: Portal vein thrombosis in patients with liver cirrhosis is usually associated to hepatocellular carcinoma. Clinical presentation of non-neoplastic portal vein thrombosis (PVT) in cirrhotic patients has not been specifically studied and risk factors of PVT in this group of patients are still poorly understood. METHODS: We studied all patients with PVT and liver cirrhosis admitted to our Unit from January 1998 to December 2002. They were paired (by gender, age and Child-Pugh score) to a group of cirrhotic patients without PVT and screened for acquired and inherited thrombophilic risk factors. These factors together with the site of thrombosis and the severity of the liver disease were correlated to the clinical presentation of PVT. RESULTS: Out of a total of 701 cirrhotic patients admitted to our hospital and routinely screened with Doppler ultrasound, 79 (11.2%) were found to have PVT. Of these, 34 (43%) were asymptomatic and 45 (57%) were symptomatic (31 presented with portal hypertensive bleed and 14 with abdominal pain, 10 of whom had intestinal infarction). Mesenteric vein involvement was never asymptomatic and lead to intestinal ischemia or infarction. Most patients were in class Child-Pugh B and C. Among thrombophilic risk factors studied only the mutation 20210 of the prothrombin gene resulted independently associated to PVT. CONCLUSIONS: Portal vein thrombosis may be completely asymptomatic in patients with liver cirrhosis; however in more than half of cases presents with life-threatening complications such as gastrointestinal haemorrhage and intestinal infarction. Cirrhotic patients with PVT usually have an advanced liver disease and the presence of the mutation 20210 of the prothrombin gene increases more than fivefold the risk of PVT.
Elevated plasma IL-6 levels have been implicated in the pathogenesis of coronary heart disease. We have investigated the association of two polymorphisms in the promoter of IL-6 (-572G>C and -174G>C) with levels of inflammatory markers and risk of myocardial infarction (MI) in a European study of MI survivors and age-matched controls from two high-risk centres in the North of Europe, and two low risk centres in the South. IL-6 and CRP levels were similar in controls in both regions, but were higher in cases. For the -174G>C polymorphism the rare -174C allele showed a regional difference in allele frequency, being more common in the North European group (0.43 vs 0.28; p < 0.0005), where -174C allele carriers showed an apparent reduced risk of MI compared to -174GG homozygotes (OR 0.53, 95%CI 0.32, 0.86). No such effect was observed in the South or with the -572G>C in either group. Neither genotype was associated with a significant effect on plasma IL-6 levels in either cases or controls. Furthermore, no regional difference was observed in the frequency of the -572G>C SNP, suggesting that these polymorphisms are unlikely to be contributing to the observed increased risk of cardiovascular disease in Northern Europe.
The propensity to atherothrombotic disease differs in Europe, with high-risk regions located in the North of Europe and lowrisk regions in the South of Europe. The HIFMECH study (Hypercoagulability and Impaired Fibrinolytic function MECHanisms predisposing to myocardial infarction (MI) study) was undertaken to elucidate genetic and environmental mechanisms underlying MI based on investigations of postinfarction patients and healthy individuals recruited from Stockholm, Sweden, London, England (North of Europe), Marseille, France and San Giovanni Rotondo, Italy (South of Europe). In the present report, emphasis was placed on fibrinogen, a multifunctional protein, widely recognized as an independent predictor of atherothrombotic disease. The adjusted plasma fibrinogen concentration was an independent discriminator between cases and controls in London (SOR 3.58; 95% CI 1.31; 9.83), but not in the other centres. Genotyping for six beta-fibrinogen promoter single nucleotide polymorphisms was performed of which -249C/T, -455G/A and -854G/A were used in analysis as a consequence of the linkage disequilibrium pattern. Four haplotypes, with similar distribution across Europe, were detected: CGG (46.7%), CAG (20.3%), TGG (18.2%) and CGA (14.8%). A significant haplotype effect on plasma fibrinogen concentration was observed in patients (p < 0.001) but not in controls (p = 0.08). The -455G/A genotype related to plasma fibrinogen concentration amongst patients along with centre and IL-6 concentration (together explaining 11.5% of the variation), whereas predictors amongst controls included centre, body mass index, IL-6 and smoking habit (explaining 15.7%). Thus, plasma fibrinogen concentration contributes differently to MI across Europe, and a disease-related stimulus is required to evoke allele-specific regulation of fibrinogen synthesis.